Dissolving of gasses into liquids is a process in which gas is dissolved into liquid, for various purposes and processes in different industries (e.g. chemical industry, agriculture), environmental control (e.g. treating of waste liquids, etc.), and the like. The term dissolving is at times referred to also as diffusing.
Dissolving air into liquid is a common process of enriching the liquid with Oxygen by which more oxygen is provided than can be supplied by the natural rate of aeration, for example in fish farms, waste water treatment, etc., where the amount of Oxygen dissolved into the liquid is increased, for consumption by living organisms.
U.S. Pat. No. 4,752,421 discloses a method for use with an apparatus which produces jets of water through a vertical water diffuser tube by supplying individually formed air bubble masses at regular intervals, which are followed by the water being drawn under the action of the air bubble masses. The method improves the water processing efficiency and ability of the apparatus by defining the volumetric quantity of a formed air mass in relation to the diameter of the particular air diffuser tube and defining a certain relationship between the length L (m) of the tube through which the rises and the time interval T (sec) at which the individual air bubble masses are produced.
GB 2059790A discloses an apparatus for combining a liquid and a gas includes a pump for circulating the liquid in tank which includes means for maintaining a constant liquid depth d, liquid from the pump being delivered to the nozzle of an injector pump having a gas inlet, the gas liquid mixture being returned to the tank by a mixing pipe. The cross-sectional area Am of the mixing pipe and the cross-sectional area An of the nozzle are selected so that the ratio Am/An lies between 1.5 and 12, the upper limit of this ratio decreasing with an increase in the liquid depth d from 2 to 8 meters.
EP 0826640A discloses a water oxygenating device comprising an upright tubular body mounted on a base close to the bottom of a body of water and having upper and lower ends open to enable water to flow upwardly therethrough. Air lift nozzles and fine bubble dispersion air supply annular pipes serve to generate a flow of bubbles upwardly through the tubular body, the fine dispersion of air bubbles effecting enhanced oxygen transfer into the water throughout passage around a pair of shallow helical flights having an angle of approximately 10 DEG to the horizontal. The fine bubble air dissolving commences outside of the tubular body to provide a gentle mixing action and thus maximum oxygen transfer within the tube where the water and oxygen interface is retained for as long as possible.
U.S. Pat. No. 4,187,263 is directed to an apparatus for causing circulation within a large body of fluid. The apparatus comprises a “large bubble” generator exposed to the pressure of the fluid at a predetermined level, a vertically extending standpipe, an inverted siphon between the standpipe and the generator, and a transverse connection between the standpipe and a vertically extending stackpipe. Upon generating a large gas bubble into the stackpipe, the gas acts as a piston within the stackpipe, pushing liquid upwardly therethrough, and thereby drawing liquid into the bottom. The continuous passage of such large bubbles through the stackpipe results in a current flow circulation through the large standing body of liquid. The advantage of the present type of large bubble generator, is that the generator can be placed at a position beneath the surface of the standing body of liquid a distance limited only by the rapidity at which a large bubble can be generated, as it is desirable that in steady state operation, a large bubble enter the stackpipe before the preceding large bubble has exited from the top.